Yoga Vasistha was written by the great poet Valmiki in the form of a
dialogue between Sage Vasistha and his pupil young Prince Rama. It gives
a magnificently detailed exposition of the subtleties and insights of
Yoga Vedanta through didactic instruction, answers to doubts, parables
and stories within stories. Upashama Prakarana Section 64. How vichar leads you to enlightenment.